Straw Bale Research Articles

Social Enrichment Improves Affective State and Foraging Behavior Compared to Physical Enrichment, While Maintaining Growth Performance in Broiler Chickens

Environmental enrichment is key for improving the broiler welfare in intensive production systems. This study lasted for 43 days and evaluated the effects of physical and social enrichment on broiler welfare. A total of 96 one-day-old male broilers were divided into two treatments: control treatment, provided with physical enrichment (n = 48) including perches, platforms, and straw bales; and social treatment (n = 48), involving regular positive interactions with a human. The behavioral repertoire, footpad health, taste preferences for sweet and umami compounds, affective states (through tonic immobility and attention bias tests), and growth performance were evaluated. No effects were found for feeding, drinking, locomotion, lying, or standing behaviors, although differences were observed at specific time points: the Social group had more feeding time on day 21 (p = 0.046), while physical treatment showed reductions on days 28 and 35 (p < 0.001). The Social group showed increased drinking on day 42 (p < 0.001), reduced locomotion (p = 0.022), and increased lying (p = 0.046) on day 42. Foraging was higher in the Social group (p = 0.027), but preening showed no differences. Footpad lesions showed no significant differences. The Control group preferred sucrose 100 mM (p = 0.022), but no preference for MSG 300 mM was observed. With regard to tonic immobility, the Control group showed a tendency towards larger durations (p = 0.078), indicating a potential increase in fearfulness. In the attention bias test, although the freezing behavior increased, the latency to begin feeding was shorter in the Social group (p < 0.001), suggesting an improved affective state. Lastly, no significant differences were observed for any of the growth parameters, including average daily feed intake, average daily gain, feed conversion ratio, or final body weight, indicating that the Social group maintained productivity. This approach provides a practical solution for improving the quality of life for broilers in intensive systems.

Design and Test of a Traction Side-Pull Square Straw Bale Pick-Up-and-Stack Truck

To address the issues of limited one-time loading capacity, single functionality, and low automation level in existing square straw bale pickers, a large automated square straw bale pick-up-and-stack truck that integrates picking, stacking, transporting, and bundling functions has been developed, combining the technical advantages of one-time field removal and storage of bales. We innovatively designed a side-pulling traction mechanism that can realize the rapid transition between the transporting state and working state of the machine; a picking device that can complete the continuous action of forking, lifting, turning positioning, and de-forking; and a bundling device that can realize the adjustment of the attitude of square straw bales. Response surface tests were conducted on the prototype to determine the key structural and operational parameters, using the bundle completion rate and regular bale rate as evaluation indicators. Regression and significance tests were performed on the machine’s forward speed, chassis frame offset, and the ground clearance of the fork tine to determine the influence and priority of these factors on the evaluation indicators. Through multi-objective function optimization of the regression model, the optimal parameter combination was found to be a machine forward speed of 15.5 km/h, a chassis frame offset of 2126 mm, and a fork tine ground clearance of 225 mm, resulting in a bundle completion rate of 98.85% and a regular bale rate of 96.96%. Subsequent field tests with the optimized parameters showed that at a machine forward speed of 15.5 km/h, a chassis frame offset of 2126 mm, and a fork tine ground clearance of 225 mm, the bundle completion rate was 98.37% and the regular bale rate was 95.83%, meeting the relevant design requirements. This study can provide a reference for the design and development of straw collection and storage machinery.

U-Values for Building Envelopes of Different Materials: A Review

In recent decades, the issue of building energy usage has become increasingly significant, and U-values for building envelopes have been key parameters in predicting building energy consumption. This study comprehensively reviews the U-values (thermal transmittances) of building envelopes made from conventional and bio-based materials. First, it introduces existing studies related to the theoretical and measured U-values for four types of building envelopes: concrete, brick, timber, and straw bale envelopes. Compared with concrete and brick envelopes, timber and straw bale envelopes have lower U-values. The differences between the measured and theoretical U-values of timber and straw bale envelopes are minor. The theoretical U-values of concrete and brick envelopes ranged from 0.12 to 2.09 W/m2K, and the measured U-values of concrete and brick envelopes ranged from 0.14 to 5.45 W/m2K. The theoretical U-values of timber and straw bale envelopes ranged from 0.092 to 1.10 W/m2K, and the measured U-values of timber and straw bale envelopes ranged from 0.04 to 1.30 W/m2K. Second, this paper analyses the environmental factors influencing U-values, including temperature, relative humidity, and solar radiation. Third, the relationship between U-values and building energy consumption is also analysed. Finally, the theoretical and measured U-values of different envelopes are compared. Three research findings in U-values for building envelopes are summarised: (1) the relationship between environmental factors and U-values needs to be studied in detail; (2) the gaps between theoretical and measured U-values are significant, especially for concrete and brick envelopes; (3) the accuracy of both theoretical and the measured U-values needs to be verified.

Design and Experiments of the Data Acquisition System for Bale Rolling Characteristic Parameters on a Large-Scale Round Bale Machine

The parameters of the roll characteristics of a large-scale round bale machine were collected in real time to investigate the bale rolling mechanism. This investigation develops a set of adaptable and highly integrated data acquisition systems for the bale rolling performance parameters of large-type round bale machines. A rolling experiment is conducted using sunflower straw as the material, and the power consumption and radial tension of the roller-round bale machine during the bale rolling process are studied. In the grass core formation stage, the round bale machine’s torque need was minimal, the radial tension of the bale remained nearly constant, and the bale chamber was primarily filled with loose sunflower straw. The motor torque and the straw bale’s radial tension both showed a tendency of gradual increase when the round bale machine was in the grass-filling stage. The motor torque and bale radial tension displayed a roughly linear trend of rapid rise as the sunflower straw continued to enter the rolling bale chamber; this was when the round bale machine was in the compressed bale rolling stage. When the power consumption of the round bale machine was measured using the data acquisition system during the test bench empty run and core-creation stage, the energy consumption comparison analysis produced a relative error of 5.8%. During the stage of bale rolling and compression, the data acquisition system monitored the power consumption of the round bale machine. The relative error was 9.5%. The data acquisition system of the round bale machine test bed has an accuracy of 90.5%–94.2% when measuring the machine’s power consumption, indicating that it is a stable and efficient system. This study provides a foundation for further research on intelligent the roller-round bale machine.

Promoting Circular Economy of the Building Industry by the Use of Straw Bales: A Review

Over the past decade, the concept of a circular economy has increasingly gained attention as a framework for guiding businesses and policymakers. Given its significant environmental impact, the building industry plays a pivotal role in the transition toward a circular economy. To address this, our review proposes a bio-based building material, specifically straw bale, which elaborates on the circularity of bio-based buildings based on the 3R principles of a circular economy: reduce, reuse, and recycle. In terms of the “reduce” principle, straw-bale buildings can reduce construction waste, the environmental impact, energy requirements, and carbon emissions. Regarding the “reuse” principle, straw-bale buildings utilize agricultural waste resources and are easily disassembled due to their prefabrication. As for the “recycle” principle, straw-bale buildings can undergo physical, biological, and biochemical conversion processes (thermochemical conversion), yielding both wooden composite boards and potential biogas and biomass fuels for electricity and heating. This study evaluates the contribution of straw packaging construction and the use of straw as a raw material, using the 3R principles to determine future research opportunities for the construction industry to achieve a circular economy. The results of this study offer circular economy solutions and interdisciplinary research insights for researchers and practitioners interested in the building environment.

Straw Bale Usage as Building Material

This study thoroughly investigates the use of straw bales as an alternative building material, capitalizing on their natural, eco-friendly, practical, and economical properties. Straw, utilized in construction for centuries, offers environmental and structural benefits, adjusting with sustainability practices. The global adoption of straw bale building emphasizes its advantages in thermal insulation, durability, fire resistance, low embodied energy, and sound insulation. While recognizing these benefits, the study addresses difficulties in moisture management and mold growth, stressing the need for careful consideration during implementation. Thus, this paper aims to contribute to the ongoing discourse on straw bale building, offering valuable insights and recommendations for architects seeking sustainable alternatives in the construction industry. Furthermore, the study underscores the importance of continuous research and innovation to overcome limitations and enhance the efficiency of straw bale architecture. By fostering a deeper understanding of the problems and opportunities associated with this eco-friendly building method, this paper tries to encourage the building industry to embrace sustainable practices and contribute to a greener future.

Transformational green sustainable concepts in the field of infrastructure

In this comprehensive study, we explore the multifaceted world of green sustainable construction, highlighting innovative techniques and materials. This article presents an insightful exploration of green sustainable construction, focusing on the crucial aspects of architectural design, judicious material selection, and the adoption of optimal structural designs. Through comprehensive literature research supplemented by practical examples, it highlights several innovative construction methodologies that are at the forefront of green sustainable development. These include the use of lightweight framing, cladding systems, autoclaved aerated concrete (AAC), rammed earth, and straw bale construction, each contributing uniquely to environmental sustainability. The study brings to light the looming issue of raw material scarcity due to excessive exploitation, urging for sustainable material management in construction. It stresses the urgency of implementing effective pollution control measures within the construction sector, asserting that such practices are not just beneficial but essential for environmental conservation and sustainable development. This research contributes significantly to the field by providing a foundation for future exploration and advancements in sustainable construction practices.

Environmental Enrichment Has Minimal Impact on Fresh and Processed Meat Quality of Turkeys

The objective of this study was to determine impacts of environmental enrichment (EE) on turkey meat quality. A randomized complete block design was used with commercial turkeys (n = 420) randomly assigned to 6 EE treatments (control [C], pecking block [PB], platform [P], wooden platform þ straw bale [PSB], straw bale [SB], and tunnel [T]) across 24 pens (16 to 18 turkeys/pen). At 19 wk, turkeys were weighed (live weight [LW]), and 6 birds per pen were harvested, a subset (n = 96 carcasses) fabricated into wings, drumsticks, and boneless breasts and thighs. From the breast and thigh, samples were taken for pH and drip loss. From the breast, samples were taken for instrumental color and shear force, with remaining breast portions further processed into boneless turkey breast logs. From each log, slices were taken for packaged purge loss (PPL), expressed moisture loss (EML), instrumental color, and texture. All EE treatments were analyzed using PROC GLM. For LW, SB turkeys were lightest, PB turkeys were heaviest, and T, PSB, C, and P were intermediate (P = 0.01). For fresh turkey, EE treatment did not impact the fabrication values, fresh breast color, breast or thigh drip loss, or breast or thigh pH (P > 0.05) and had minimal impact to thigh color with significant differences only in the b* values (P = 0.04). For processed turkey, EE did not impact processing yield, PPL, a*, b*, or texture (P > 0.05). For L*, SB, T, P, and PSB were lighter, C were darker, and PB had intermediate values (P = 0.02). PB, PSB, C, and T had greater EML loss, P had the least, and SB had intermediate EML (P = 0.04). The results indicate some variations of turkey quality due to EE, but the impacts of specific enrichments were not consistent across quality parameters.

Emerging Trends in Sustainable Materials for Green Building Constructions

The national decision on the neutrality of global carbon emission as well as decarbonization focus drives the need for the transformation of the building and construction sector of the economy. Thus, green building materials and its production is a better means of achieving depletion in carbon emission. More so, to achieve excellent green development in the construction industry as well as the goal of decarbonization, there is a need to investigate the emerging trends in the sustainable materials for green buildings. Hence, this study focused on the review of some of the existing green materials and its effect on the building construction. Findings from literature studies revealed six different green building materials which include bamboo, cork, straw bale, reclaimed wood, sheep’s wool and hempcrete. It was reported that each of the green material have excellent thermal insulation property, low emission of CO2 and has the ability to be recycled, thus, bringing sustainability in the circular economy as well as eco-friendliness of the material. These findings expand the scope of green materials application and can inform the government to formulate policies that will encourage sustainable green buildings. Keyword: Sustainability, Development, Green Buildings, Green Materials, Emissions

Concept Design of the WRB-6 Water-Tube Boiler with a Stepped Grate and a Furnace for Burning Straw Bales in a Cigar System

The article presents the conceptual design of the solid fuel from the forest and sawmill production waste and agricultural waste biomass-fired water boiler. The project was supported by thermal and flow calculations. The designed WRB-6 boiler is a 3-pass unit with a fully screened furnace chamber and is equipment of a local biomass heating plant. It is fired with biomass, transported over no more than 30 km. The furnace has a double function – dual fuel. Both fuels can be burned simultaneously or alternately, depending on seasonal availability. In the front part there is a channel for feeding and burning large bales of cereal straw. The lower closure of the chamber is a mechanically inclined grate for the combustion of wood biomass in the granulation of chips. As part of the work, calculations of the amount of biomass fuels possible to be obtained on the local market with economy of delivery were also performed. As a result of the calculations, the temperatures of water and flue gas at the outlet, boiler efficiency, slagging and impurity indices for biomass were also presented.

Production and use of dry-rolled hybrid rye grain as a replacement for barley grain on growth performance and carcass quality of feedlot steers.

The objectives were to compare cereal grain and straw yield between barley and hybrid rye (HR) and to evaluate whether the inclusion of dry-rolled HR grain as a replacement for barley grain affected feed intake and growth for growing cattle, and feed intake, growth, and carcass characteristics for finishing cattle. Crop yield was measured by directly weighing harvested grain and straw bales (n = 3 plots/grain type). Three-hundred sixty steers with an initial body weight (BW) of 348 ± 40kg were stratified by BW and randomly assigned to 1 of the 24 pens during the growing phase (n = 8; 65 d). The control diet (BCON) included 60.22% barley grain with HR included by replacing 50 (BMID) or 100% (BHIGH) of the barley grain on a dry matter (DM) basis. Steers were re-randomized for the finishing phase (n = 6; 118 d) and treatments included a control diet containing 88.60% barley grain (FCON) with HR replacing 33 (FLOW), 67 (FMED), or 100% (FHIGH) of the barley grain (DM basis). The grain yield was greater (P = 0.04) and straw yield tended (P = 0.06) to be less for HR than barley. There were no effects of HR inclusion on DM intake (DMI) or G:F during the growing phase, but average daily gain (ADG) responded quadratically (P = 0.02) with cattle fed 50% HR having the greatest gain. During finishing, DMI decreased linearly as HR grain inclusion increased (P < 0.01). ADG initially increased from FCON to FLOW followed by a decrease with increasing HR inclusion (quadratic, P < 0.01), but G:F was not affected. Hot carcass weight was greatest for FCON with the magnitude of difference between FCON and the HR treatments increasing with increasing inclusion of HR (quadratic, P = 0.02). There was a linear increase in dressing percentage (P = 0.02) and a linear reduction in back fat thickness (P = 0.04) with increasing inclusion of HR. Increasing the inclusion of HR during finishing cubically (P < 0.01) affected the proportion of minor and severe liver abscesses with an average of 34.60% severely abscessed livers when HR was included compared to 11.11% for BCON. HR may have greater grain yield than barley, and partial replacement of barley grain with HR may improve ADG without affecting DMI or G:F during the growing phase. However, replacing barley grain in finishing diets with HR decreases DMI, and increases the risk of minor and severe liver abscesses, but does not affect feed conversion, suggesting HR should not replace more than 33% of the barley grain to maintain ADG.

Research of biotechnological, physical and mechanical properties and fractional composition of pressed feed bales

To develop and optimize the parameters of a compressed feed chopper device, a comprehensive understanding of the biotechnological, physical, and mechanical properties of the processed compressed feed is essential. An experiment was conducted to analyze the fractional composition of compressed straw, alfalfa, and camel thorn. The compressed feed was divided into fractions based on length categories: up to 30 mm, 30-50 mm, and 50 mm. The fractional composition was determined relative to the total mass, and size-mass indicators were analyzed. Results indicated that fractions longer than 50 mm constituted 10.42 kg or 78.2% of the straw bale, with an average mass of 13.3 kg. Fractions in the 30-50 mm range accounted for 2.34 kg or 17.6%, while fractions shorter than 30 mm made up 0.56 kg or 4.2% of the total mass. The average density of the straw bale was calculated to be 83.1 kg/m3. Subsequent experiments revealed the diameter range of stalks for straw (1.5-5.5 mm), alfalfa hay (1.5-4.0 mm), and camel thorn (2-10 mm). Samples of each feed type, ranging from 50 mm to 100 mm in length, were selected for bending and breaking experiments.

Mechanical and thermal properties of environmentally friendly straw boards

Straw is an environmentally friendly, cost-effective, and abundant raw material for building boards. To assess the feasibility of using straw boards in building envelops, such as being alternative sheathing panels in light-gauge steel-framed members, for instance, walls and floors, both the mechanical and thermal properties of straw boards with high densities were investigated. The straw boards involved in this study include five wheat straw strand boards (WSSB12, WSSB15, WSSB18, WSSB25, and WSSB30) and a paper straw board (PSB58) named with a combination of the respective board type and thickness. Among them, the WSSBs are a type of straw composite, while the PSB is an improved straw bale with sheathing paper, which is mainly for enhancing the board integrality. Moreover, the former is composed of smashed straw fibers and isocyanate resin and has higher densities, while the latter is without using any artificial binders. Mechanical properties, including compression, tension, and bending properties, were investigated by tests and a proposed prediction method of tensile strength. In the experimental studies of compression properties, the failure modes, characteristics of load-deformation curves, and the differences in material directivity were analyzed and discussed. The results show that the WSSBs were considered to be transverse isotropic material with brittle characteristics in the plane. Then, the experimental studies of bending properties were carried out, and the results show that the bending strength is less than the compressive strength for WSSBs, while the bending strength of PSB is greater than its compressive strength. And the bending elastic modulus and the compression elastic modulus are close for either the WSSBs or the PSB. Furthermore, finite element models of the bending test specimens using the user material subroutine UMAT were developed to predict the tensile strength ft, and the constraint checks were conducted. It is verified that the prediction results of ft are believable, and the prediction method proposed is feasible. For the thermal properties of straw boards, tests were performed using the temperature control box - heat flux meter method, and the thermal conductivity λ was mainly focused. It is found that a significant linear correlation exists between the density ρ and λ, and the proposed fitting formula can be used to predict the thermal conductivities of such materials. Finally, brief comparisons of the mechanical and thermal properties between the straw boards and the oriented strand boards (OSBs) were conducted, and the feasibility of applying straw boards in building envelops, such as alternative sheathing panels with load bearing and insulation demands was verified. This study contributes to popularizing the application of straw boards in engineering structures by a compromising consideration of mechanical and thermal properties, which plays a positive role in the development of green buildings.

Straw bale construction towards nearly-zero energy building design with low carbon emission in northern China

With the aim of achieving carbon neutrality, bio-based construction is of increasing interest for decarbonization globally. Among the potential candidates, straw bale is promising due to its ready availability and energy efficiency benefits. However, thermal conductivities of straw bales can vary greatly due to construction details, which may lead to failures in meeting nearly-zero energy building (nZEB) design standards in real practice. In the context, this study applied thermal property and carbon emission assessment of full-size straw bale walls (SBWs) and construction of an experimental building in northern China. The results demonstrated that the thermal conductivities of different monitoring portions of the SBWs ranged from 0.067 to 0.088 W·m−1·K−1. This resulted in U-values (0.16 W·m−2·K−1) marginally higher than the lower limits of nZEB design, indicating the importance of addressing thermal bridging issues of SBWs. The SBWs without additional insulation layers therefore can satisfy nZEB design standards in the severe cold region after certain adjustments. Besides, when not accounting for carbon sequestration, SBWs generated the lowest emissions among the schemes in meeting U-value limits for nZEB design (at least 14.6% lower than those of timber walls), with increasing emission reductions as U-value limit decreased. The results indicated that SBW demonstrated effectiveness in carbon reductions with high thermal performance. The findings of the research can facilitate application of straw bales and development of clean construction and net-zero design in northern China.

Building decarbonization by means of ancient techniques. Assessment of environmental impact, energy performance and mechanical safety

The construction sector seeks for more environmentally friendly construction materials. Henceforth, materials such as earth-based materials (EBM) or straw bales (SB) are lately becoming more popular for architectural designs. Notwithstanding, their technical aptitudes are major concerns since few studies have assessed them from an integral perspective. Thus, this article aims to assess their performance by considering different approaches such as energy consumption, thermal comfort, mechanical response, and environmental impact. Results were compared to those provided by conventional materials such as fired bricks and concrete blocks. A typical detached house was modelled by following Chilean building codes. The energy assessment was determined by dynamic calculations while mechanical aptitude was assessed by means of push-over analysis. Finally, the environmental impact in a cradle-to-grave perspective was determined through the ReCiPe methodology. Results show that EBMs and SB significantly reduce the environmental impact when compared with traditional materials. Thus, for human health, resource depletion and ecosystem quality an average of 40, 30 and 20%, respectively, were obtained by choosing SB or EBM. Since all cases did accomplish thermal insulation requirements, no significant differences were found in energy consumption. However, the higher thermal capacity of EBMs and the higher thermal resistance of SB, certainly led to savings (approx. 5%). Finally, for a medium intensity earthquake, negligible damage may be expected, and immediate occupancy levels are showed from capacity curves. It is concluded that EBMs and SB significantly reduce the environmental impact of the building and lead to satisfactory results in terms of energy performance and mechanical aptitude.

Exploring Low-Carbon Design and Construction Techniques: Lessons from Vernacular Architecture

This paper presents a comprehensive review of low-carbon materials and construction techniques commonly used in vernacular buildings. The study highlights the relevance of vernacular architecture in the context of the shift towards sustainable construction practices. A combination of a climatic zone map, vernacular language type map, and continent map is used to identify the vernacular regions. Eight bio-based low-carbon materials, including wood, adobe, rammed earth, cob, sod, thatch, bamboo, and straw bales, are discussed, along with their characteristics, availability, and environmental impacts. The construction techniques associated with these materials are explained, emphasizing their simplicity, cost-effectiveness, and adaptability. The paper also explores two important design approaches: design for disassembly and design for modularity that were used in vernacular building. The review found the use of low-carbon materials and construction techniques derived from vernacular architecture can contribute to minimizing waste, reducing environmental impacts, and promoting a circular economy in the building industry. This research provides valuable insights for architects, engineers, and policymakers seeking sustainable alternatives in the construction sector.

Compressive load resistance of straw bale assemblies under concentric and eccentric loading

To reduce the significant carbon emissions associated with construction materials, there is growing recognition of the potential for bio-based resources, including materials derived from agricultural crops such as straw, hemp and flax. The biogenic carbon stored with plant based materials can significantly reduce carbon emissions compared to other products. Uses of bio-based materials are however generally limited to non-structural, in particular as insulation, but in contrast to many other solutions straw bales can also be used structurally in low-rise construction. Despite the use of straw bales for over 100 years there is still relatively little known about their compression performance, and there are no recognised guides or standards to support structural engineers. This paper describes an experimental study into the load carrying capacity of straw bale wall assemblies. In keeping with practice in the UK, and different to previous North American studies, the wall plates do not directly bear onto the plaster coats. The aim of the paper is to characterise and compare the vertical load carrying performance of straw bale walls without and with plaster coatings, and study the effect of wall height, plaster use, and load eccentricity on compressive resistance. A series of wall assemblies were built from stacking 1 m long wheat straw bales. Wall assembly heights varied with the number of bale courses: one, two, three and four bales high. In total results from 29 tests are presented. Key findings of the study concern the influence of load eccentricity, use of plaster and wall geometry on compression performance. In the absence of national guidance, the results of this experimental study will support structural engineers designing loadbearing straw bale walls.

Low-carbon Building Materials: an Overview of Innovative Alternatives to Traditional Materials

The building industry is a major contributor to global greenhouse gas emissions, accounting for approximately 40% of global energy-related emissions. Low-carbon building materials offer a promising opportunity to reduce the environmental impact of the building sector. Low-carbon building materials are those that have low embodied carbon, meaning that they require less energy and resources to produce. They can be made from a variety of materials, including recycled materials, natural materials, and sustainable materials. This study will examine the benefits, limitations, challenges, and opportunities associated with the use of low-carbon building materials. The study will focus on the different types of low-carbon building materials and technologies currently available, including straw bale, bamboo, fly ash, and CEB. The study will examine the benefits, limitations, and challenges associated with using these materials and explore the opportunities provided by their adoption. A review of academic literature, industry reports, and case studies will be conducted as part of this study.

Discrete element modelling and simulation parameters calibration for the compacted straw cube

The compacted straw cube (CSC) is the structural unit of a rectangular straw bale. A rectangular straw bale can be regarded as an ordered assembly of several CSCs constrained by strings. Straw bale is the object of mechanical operation in the straw collection, storage, management, and terminal utilisation. As a basis for studying the mechanics of rectangular straw bales, it remains a challenge to establish the CSC discrete element model incorporating the elastic, plastic, and viscous mechanical characteristics of the flexible straw and calibrate its simulation parameters. An original method of CSC discrete element modelling and simulation parameters calibration based on EDEM software was proposed. The CSC model was developed by performing virtual uniaxial compression tests with thousands of flexible straw stems using Edinburgh elasto-plastic adhesion (EEPA) as the contact model between straw stems. With compressive stress σ10 as the response value, the discrete element parameters of the CSC model were determined by the Plackett-Burman design test, the steepest climb test, and the Box-Behnken design test. The results showed that the relative error of the simulated compressive stresses σ10 was 1.04% for the 120 mm thickness of CSC. The relative errors of the CSC with 180 and 240 mm thicknesses were 3.89% and 2.6%, respectively, which validated that the model and parameters were reliable. The proposed method provides a new perspective for analysing the interaction mechanism between straw bales and mechanical components, which is significant for the development of straw management and utilisation equipment.

Comparing different environmental enrichments for improving the welfare and walking ability of male turkeys.

This study investigated age-related changes in turkey welfare measures (wounds, feather quality (FQ), feather cleanliness, and footpad condition (FCON)) and walking ability (gait) as influenced by different types of environmental enrichment (EE). Tom turkeys (n = 420) were randomly assigned to: straw bale (S), platform (P), platform + straw bale (PS), pecking block (B), tunnel (T) or control (C; no enrichment) group. Welfare measures and gait were assessed at 8, 12, 16 and 19 wk and analyzed using PROC LOGISTIC with Firth bias-correction. Better wing FQ with age was observed in turkeys in S and T groups. Turkeys in the S group had better wing FQ at 16 (P = 0.028) and 19 wk (P = 0.011) vs. 8 wk. Wing FQ (P = 0.008) was better at 19 vs. 8 wk for T turkeys. FCON worsened over time for turkeys in all treatment groups except for the S group. FCON was worse at 19 vs.8 wk for P (P = 0.024), PS (P = 0.039), B (P = 0.011), T (P = 0.004) and C (P = 0.014) turkeys and was worse at 19 vs. 12 wk for B (P = 0.038), T (P = 0.015) and C (P = 0.045) turkeys. FCON was worse at 19 vs. 16 wk for T (P = 0.007) and C (P = 0.048) turkeys. FCON was also worse at 16 vs. 8 wk for B (P = 0.046) turkeys. Gait worsened with increasing age in all treatment groups. Gait was worse at 19 wk for S (P < 0.001), P (P < 0.001), PS (P < 0.001) and B turkeys (P < 0.001) vs. earlier ages, while gait in T (P < 0.001) and C turkeys (P < 0.001) worsened starting at 16 wk.